Possible Cochin crossed with RIR?

I have a bunch of cochin hens - partridge, black and blue. They were in with a big blue and a big partridge cochin rooster. We have a RIR rooster who may have gotten in their pen once by flying over the top of the pen. All the adults are purebreds.

Could I possibly have gotten a blue chick from a blue cochin hen crossed with a RIR rooster? This chick is as blue as blue could be, but doesn't have the feathered legs. I thought feathered legs were dominant?

It would be possible to get a blue chick from the blue Cochin hen crossed with a RIR rooster. The chick could get one copy blue gene from the hen. The hen should also pass the exended black pattern on which would explain why the columbian pattern and mahogany genes from the rooster would not be visible. I've never crossed feathered legs so I'm not sure about the dominant recessive tendencies there.

Do these chicks breed true in terms of Blue (blue, black, splash) as adults? I only breed purebreds here, but I am curious I guess. I wonder if the chick will grow up to exhibit a standard blue pattern like it does as a chick or if any of the red will show through...???

Well the feathered leg thing is what I was wondering about too. If it is dominant, the feathers should be there.

The cochins are supposed to be from good stock. They are new to my flock this year so I don't know if they are going to breed true or not. Some are long backed, but, the they do have GREAT feathering, not just a few feathers. They have the full "bloomers" all the way down. I couldn't ask for better feathering in fact. But, if they are heterozygous because someone out-bred them to a non-cochin, I am going to be ticked off. I paid pretty good money for them.

I have heard of rare featherless throwbacks, but 2 out of 6 chicks? Doesn't make sense to me. It confused me so much in fact, I put "Chaps", my blue cochin roo, back in with the blue girls and I am going to hatch out a dozen to see what the feathering is like. So, if I get any without feathers, I have a problem!

Leg feathering is dominant and there are at least three different leg feathering genes. Add them up in a bird and you get thicker/more leg feathering.

If some of the chicks were truly clean legged, then it could be a concern. However if there were some fuzz going down side of the leg, that is a common expression in crosses. It's variable..

Black is dominant so yes, black/blue x RIR can produce black/blue chicks. However as the other person said, it's often leaky, showing off color on neck/saddles.. black stars are good example of leakiness in a black cross. But you also have partridges, so a leaky black/blue could be a cross between the cochin colors.

So-called "throwbacks" often are evidence the parents were heterozygous. 2 chicks could match the 25% or lower possibility from heterozygous parents or a het. feather leg cross with a clean leg.

It is good idea to breed them again to see if the problem pops up again or not. Raising those chicks you have already can be another helpful hint- if those clean leg and other chicks show RIR type in some way, it would show that he did get in and bred somebody.